Thanks for feedback...I'm fortunate that I do not have to worry about
bandwith, as the ATM network is for ADSM use.  I will play with compression
but can you tell me what the CPU penalty for using ADSM compression?
Thanks -- Perry

Lee Russon wrote:

> Perry,
>
> Consider using ADSM compression on your AIX clients as this can improve
network throughput. We tested RS/6000 AIX clients running with compression
and without and found that the backup of data took 3 times as long without
compression. If network bandwidth is not a problem then leave compression
off, but remember that more data will be processed by the server before the
data arrives on tape.
>
> We transfer all client backup data to a primary disk pool overnight and
copy the disk pool data to tape after all clients have been backed up. The
tapes are then sent to off-site storage. During the day we migrate data
from the disk pool to on-site tape to free up space for the next nights
run. This method seems to work quite well as client machines do not have to
wait for tapes to be mounted and the server has less data to process.
>
> The options you use on the clients are very similar to our own, but you
may find that increasing the TXNBytelimit may improve performance (it all
depends on how fast your HP/IBM machines are)
>
> Regards,
> Lee Russon
> Midlands Electricity plc
>  ----------
> From: McGrew, Perry
> To: adsm-l AT vm.marist DOT edu
> Subject: Tuning tips?
> Date: 10 December 1997 13:59
>
> We've just installed ADSM/MVS 3.1 on our TCP/IP 3.2 Ethernet network
> over ATM (LANE) backbone.  We have the lastest ADSM 3.x client code on
> our HP-UX 10.2 & IBM AIX 4.3 servers.
> In the dsmsched.log I am seeing:
> Network data transfer rate:        1,772.97 KB/sec
> Aggregate data transfer rate:      1,468.25 KB/sec
> We do not have ADSM compression turned on as we are using hardware
> compression on our 3494/3590 MagStar tape drives.
> Our TCPIP/MVS 3.2, the  LARGEDATABUFFERPOOLSIZE is set to 32768.
> In the HP / AIX Clients' the dsm.sys parameters are:
>    TCPWindowsize      64
>    TCPBuffsize             32
>    TXNBytelimit       2048
> Any help in identifying critical tuning points will be appreciated!
> Thanks,
> Perry McGrew
> Agway Inc.